Typhoon Shanshan is strengthening over southeastern Japan in unusually warm 30-31 degrees Celsius (86-88°F) waters. According to the Joint Typhoon Warning Center, at 11 a.m. EST on Monday, Shanshan was a Category 2 storm with winds of 105 mph and a central pressure of 958 MB, located 267 miles east-northeast of Okinawa. Moving west-northwest at 9 mph.
Satellite loops show that Shanshan has a solid area of severe thunderstorms surrounding a prominent eye, but moderate wind shears of 15-20 knots are slowing development. Shanshan's peak intensity is expected to occur Tuesday afternoon and evening (EST), when the Joint Typhoon Warning Center predicts that the typhoon will move through Japan's Ryukyu Islands as a high-end Category 3 storm with winds of 125 mph (average minute). The Japan Meteorological Agency predicts that Shanshan's peak will arrive on Wednesday morning (EDT), when the storm will last for 10 minutes, with wind speeds of 100 mph and a central pressure of 950 megawatts. Both agencies predicted that less favorable upper-level winds would cause Shanshan to weaken before making landfall in Kyushu on Thursday.
Shanshan is a storm that is difficult to predict. At 11 a.m. ET on Monday, the Joint Typhoon Warning Center predicted that the Category 1 typhoon would make landfall nearly two days later, more than 400 miles southwest of Friday's predicted landfall, with a Category 4 expected to make landfall. The models still struggle with Shanshan's track and intensity forecasts, and the Joint Typhoon Warning Center gives only medium confidence to its forecasts.
Large typhoons that make landfall in Japan are not common
According to the Joint Typhoon Warning Center, only 16 Category 3 or above typhoons have made landfall on one of Japan's four main islands (Honshu, Kyushu, Shikoku and Hokkaido) since accurate records began in 1945. The last major typhoon to make landfall was Maracas in 2016, which struck southern Kyushu, killing one person and causing more than $300 million in damage. Two Category 4 typhoons hit Japan: Shirley in 1965, which made landfall in Honshu with winds of 150 miles per hour, killing 60 people; and Yangsi in 1993, which made landfall in Kyushu with winds of 130 miles per hour, killing 48 people. deaths and $3 billion in damage. Japan has only experienced one Category 5 typhoon landfall – the infamous Typhoon Vera in 1959, which was Japan's deadliest typhoon, killing 5,098 people.
Japan's costliest typhoon
If “Shanshan” hits sufficiently densely populated areas with Category 2 or higher intensity, it could become one of the costliest typhoons in Japan's history. According to EM-DAT's inflation-adjusted damage estimates, these are the costliest Japanese typhoons since 1945:
Mireille, 1991, $22 billion
Hagibis, 2019, $20 billion
Fuck, 2018, $15 billion
Song Da, 2004, $15 trillion
Faxai, 2019, $11 billion
Flo, 1990, $9 billion
Bart, 1999, $9 billion
Sarah, 1986, $6 billion
Vera, 1959, $6 billion (5,098 deaths)
Ada (Murazaki), $7 billion, 1945 (3,746 deaths)
The list does not include the $12 billion worth of flooding damage in southern Japan in July 2018, which was caused by the presence of a stationary seasonal frontal boundary enhanced by residual moisture from Typhoon Prapiroon.
looking back on the past Japan’s only ever Category 5 landfall: Typhoon Vera (1959)
On September 26, 1959, Typhoon Vera made landfall on the coast of Honshu, Japan as a Category 5 storm with winds of 160 mph and brought a catastrophic storm surge of 3.55 meters (11.6 feet) to Nagoya. The storm surge caused serious damage to the town of Handa southeast of Nagoya, turning the port into a “sea of death”. The huge waves killed 300 people and destroyed 250 houses. Vera killed 5,089 people, injured 38,000, left 1.6 million homeless, and caused $6 billion in damage ($2,023).
In the aftermath of Hurricane Vera, levees and sea walls were built to protect Nagoya from storm surges comparable to those caused by Typhoon Vera, floodgates were installed at subway station entrances to prevent flooding, and many other flood prevention measures were taken. Therefore, Nagoya is less susceptible to storm surges from Category 5 storms. A 2010 storm surge study by Susunis and Kafari found that “with rare exceptions, the current levee system is adequate to withstand another attack by Typhoon Vera.”
However, global warming coupled with rising sea levels is increasing the risk of typhoons in Japan, even stronger than Vera. Sea levels in Nagoya have risen about 20 centimeters (8 inches) since 1959, making it easier for storm surges to breach the seawall. A 2020 study found that future global warming is expected to bring “the largest potential typhoon” to Nagoya, with a 10-minute average wind speed of 60 m/s (134 mph) and a central pressure of 885 mb. If the storm hits at high tide, it could generate a storm surge two meters (6.6 feet) higher than that of Vera, overwhelming Nagoya's flood defenses and sending destructive water flow between buildings along narrow city streets. flows between spaces at speeds exceeding 10 m/s (23 mph).
If Hurricane Vera happened again today, the wind damage would be even greater due to increased population and wealth. The population of the Nagoya metropolitan area was 4 million in 1959, and the current population is 9.6 million. A 2009 RMS study found that repeated wind damage from Super Typhoon Vera would cost $20 billion to $26 billion (2024 USD). Storm surges could cause billions of dollars in additional damage, primarily in areas beyond city flood walls.
Hurricane Horn hits Hawaii's Big Island
Hurricane Horn made its closest approach to the Big Island of Hawaii on Sunday morning, passing about 50 miles south of South Cape. At the time, the hurricane had sustained winds of 85 mph and a central pressure of 988 MB. The strongest winds on the Big Island appear to be driven by a localized downslope mountain wave effect, as easterly winds cascade down west-facing slopes — the same mechanism that sparked Maui's catastrophic fires last year. Horn brought heavy rain to the east side of the island, with a 36-hour rainfall total of 22.38 inches. The hurricane left more than 20,000 customers without power, but no major damage was reported.
Hot on the heels of Horn was Hurricane Gilma, which peaked as a Category 4 storm Sunday morning with winds reaching 130 mph. Gilma is expected to weaken to a remnant low with winds of 35 mph by Friday, when it is expected to pass north of the Hawaiian island of Maui. Gilma is followed by Tropical Storm Hector, which is expected to weaken to a tropical disturbance before reaching the Hawaiian Islands this weekend.
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